java泛型&bean copy list

Posted 2021-01-31 遥远2

参考：https://www.oracle.com/technetwork/cn/articles/java/juneau-generics-2255374-zhs.html

E：元素
K：键
N：数字
T：类型
V：值
S、U、V 等：多参数情况中的第 2、3、4 个类型

 

例子代码：

public static <T,S> List<S> copyList(List<T> fromList,Class<S> toObj) {
    if (CollUtil.isEmpty(fromList)) {
        log.error("Utils-->copyList:fromList is null or have‘nt data");
        return null;
    }
    if (null == toObj) {
        log.error("Utils-->copyList:toObj is null");
        return null;
    }
    List<S> toList = CollUtil.newArrayList();
    fromList.forEach(f->{
        S t = null;
        try {
            t = toObj.newInstance();
        } catch (Exception e) {
            e.printStackTrace();
        }
        BeanUtil.copyProperties(f, t);
        toList.add(t);
    });
    return toList;
}

调用：

@Test
public void testCopyList() throws Exception {
    List<DictDO> fromList = CollUtil.newArrayList(new DictDO("code1","name1"),new DictDO("code2","name2"));
    List<DictPojo> toList = Utils.copyList(fromList, DictPojo.class);
    Console.log("{},{}",toList.size(),CollUtil.isEmpty(toList));
    if (null != toList && toList.size()>0) {
        toList.forEach(d->{
            Console.log(d);
        });
    }
}

输出：

2,false
DictPojo(code=code1, name=name1)
DictPojo(code=code2, name=name2)